This invention relates to an improved structure of tact switch, particularly to a tact switch that can prolong lifetime of its inside components.
A so-called tact switch widely applied in computer, remote controller, mouse, light pen, etc is formed by disposing a reed dome then a pushbutton, from the bottom to the top, on a seat body with an open face, wherein the seat body is covered peripherally by a closure for keeping each inside element in place so that the reed dome will be pressed to contact an electrode thereunder and release an output signal when the pushbutton is pressed.
The tact switch purchasable locally so far may be grouped into three categories according to the material adopted: a first one containing a rubber pushbutton and a Be-Cu or Pb-Cu reed dome; a second containing a plastic pushbutton and a reed dome as above; and a third containing a plastic pushbutton as above and a more expensive high quality reed dome.
When the first tact switch is pressed, the pushbutton will contact the reed dome softly that ensures a longer lifetime with an average press-durability of one million times. However, after a long duration, the rubber pushbutton will become hardened and is liable to get impaired, and in addition, it may reflect a damp and acerb feeling when being touched.
The plastic pushbutton of the second can keep its own surface tidier and more flush than that of the rubber in a long duration, however, as the bottom thereof touches the reed dome directly, the latter will inevitably wear away gradually with an average press-durability of one hundred thousand times--about one tenth of the rubber made.
The third is a combination of a plastic pushbutton and a more expensive high quality reed dome with a press-durability about the same as the first.
In view of the forgoing respective defect, this invention is to provide an improved structure of long lifetime tact switch without increasing production cost.